This application claims priority to German Patent Application No. 102 23 940.1, filed on May 29, 2002, and German Patent Application No. 202 19 113.3, filed Dec. 9, 2002.
The invention relates to a device for guiding the airflow around a roof opening, and more particularly a device that guides air flow around the front edge of the opening of a sliding roof.
Known sliding roofs have a wind deflector and at least one additional deflector movably fastened to the wind deflector and adapted to protrude vertically upwards with respect to the rear edge of the wind deflector. The wind deflector and the additional deflector are each movable between an unextended position and an extended position. These additional deflectors are provided to prevent a thrumming noise from occurring when the sliding roof is open by avoiding generation of low-frequency pressure pulses responsible for the thrumming.
Additional known deflectors are concealed by the cover of the sliding roof in the closed position. This is why currently known sliding roof structures having a wind deflector device and why the cover needs a lot of space in the Z-direction, i.e. in the vertical axis of the vehicle. Moreover, the cover readily exposes the additional deflector located between the wind deflector and the cover when the deflector travels backward, which is not always desirable due to air flow conditions.
There is a desire to provide an airflow guiding device that allows a higher degree of flexibility in its construction and shape than currently known devices.
There is also a desire to provide a device which has a simple construction, consists of few parts and can reliably be operated at high comfort. Moreover, there is a desire for such a device to be distinguished by a low weight.
One embodiment of the invention is directed to a device for guiding an airflow in a region of a roof opening in a motor vehicle roof comprises a wind deflector and at least one additional deflector. The additional deflector has a rear end face and is movably fastened to the wind deflector and adapted to protrude vertically upward with respect to a rear edge of the wind deflector. The wind deflector and the additional deflector are each movable from a normal, unextended position into an extended position. The additional deflector, in its normal position, is fastened to an underside of the wind deflector and moves along the rear end face of the wind deflector when it is moved into the extended position.
To simplify the device""s construction and reduce its weight, the inventive device according to one embodiment has a mechanical control that is connected to the additional deflector and has a roof-fixed permanent coupling point. During at least the raising motion, the wind deflector engages the mechanical control and displaces the additional deflector to move the additional deflector toward its extended position by displacement of the wind deflector. The invention therefore does not require a separate electromotor drive for the additional deflector. Instead, movement of the wind deflector itself is converted by a mechanical coupling into a motion of the additional deflector. In other words, a constrained coupling action between the two motions is produced, at least in the direction of the extended position of the additional deflector.
This simple mechanical coupling reduces the expense for a separate drive mechanism to move the additional deflector, and it can be configured to be simple and contain few parts. As noted above, the control device is fixed to the roof through the coupling point and also fixed to the wind deflector to achieve a displacement of the control device by motion of the wind deflector relative to the roof. Alternatively, the mechanical control device can also be coupled to an element that travels on the vehicle roof. An energy storing device may also be incorporated to assist in moving the additional deflector to the extended position and/or the retracted position.
According to one embodiment, the control device is coupled to an energy storing device that is biased to move the control device and to bring the additional deflector into the normal position. This embodiment has the advantage that the additional deflector is able to yield due to the energy storing device. This energy storing device preferably is a spring mechanism which can set the flexible force-transmitting means under permanent tension and/or bring the additional deflector into the normal position when the wind deflector is retracted.
In another embodiment, the additional deflector may be displaced from the normal position from below the wind deflector in the normal position along a path toward the extended position until it protrudes beyond the rear edge of the wind deflector. In other words, the additional deflector travels along a path rather than being pivoted; a combined travel-and-pivot motion would also be possible, of course. Alternatively, the additional deflector may be stored within a case on the underside of the wind deflector and emerge from the case when the wind deflector approaches its extended position.
In a further embodiment, the control device for the wind deflector, and preferably for the additional deflector, raises the wind deflector and/or the additional deflector as a function of the vehicle speed, the position of the cover, the degree of how far the roof is opened and/or the sound pressure in the interior of the vehicle. This is achieved by using appropriate sensors or constrained guide means, ensuring that the deflector is not raised inappropriately if a thrumming noise is not expected or detected.